YanniD said:

Whilst it would be nice to have a menu driven BD with extras, I personally would much rather have an mkv of the movie with a single lossless soundtrack and all other soundtracks downloadable separately so that I can mux them in as required without having to download more than I need.

In the fullness of time, when Harmy releases the full BD, perhaps he can make available the Bluray structure and supplementary files so that I can simply shoehorn the mkv (converted to m2ts) to match.

I also think any extras should be released on a "bonus" disc.

HD-DVD had a really great feature that allowed external subtitles and even soundtracks to be incorporated into the movie on the primary disc, without them having to be on the primary disc. I really miss that flexibility with Bluray.

I certainly wish Harmy the best in tackling the weird and wonderful world of Bluray authoring.

That is pretty much the plan as I understand it - to have one file, a .mt2s file, and then a separate download of folder structure for putting together a disc. You'll be able to take that m2ts, use mkvmerge, uncheck the audio you don't want, and have an mkv of exactly what you do want :)